Stacking arrangement for sheet metal strips, especially for surface sensitive sheet metal strips



y 20, 1965 G. MORATH ETAL 3,195,888

ESPECIALLY STACKING ARRANGEMENT FOR SHEET METAL STRIPS,

FOR SURFACE SENSITIVE SHEET METAL STRIPS 2 Sheets-Sheet 1 Fig. 1

lift EN TOP United States Patent 3,195,888 STACKING ARRANGEMENT FOR SHEET METAL STRIPS, ESPECIALLY FOR SURFACE SENSITIVE SHEET METAL STRHS Giinther Morath, Walter Waldura, and Klaus Schneider,

St. Ingbert, Saar, Germany, assignors to Verwaltungsgesellschaft Moelier und Neumann Gifene Handelsgesellschaft Filed May 14, 1962, Ser. No. 194,453 Claims priority, application Germany, May 15, 1%1, M 49,055; Nov. 22, 1961, V 21,635 Claims. (Cl. 271-78) The invention is concerned with the problem of stacking sheet metal strips, especially smooth or polished sheet metal strips having surfaces which are easily susceptible of being scratched or marred. It has been found that the high amount of scrap obtained during the deep drawing of such sheet metal strips is due to scratches in the surface of the metal strips. Even small damage of this type permits breaking of the sheet metal at that particular point-whenever it comes to lie at a sharply bent edge during the deep drawing operation.

' Many suggestions have already been made to stack sheet metal strips without causing scratches. A known principle to which this invention is related comprises an endless conveyor device rotating in a vertical plane and provided in the form of two roller chains between which conveyor rollers are arranged to serve as sheet metal carriers. The upper side of the roller conveyor is conducted over the stacking table and by means of four pairs of chain rollers is returned below the table. The sheet metal strips are transferred from a driving roller pair to the endless conveyor. When they come to rest at a front stop above the stacking table the conveyor rollers are withdrawn from below the sheet metal strips so that it is lowered first at the edge which is remote from the front stop. The subsequent non-loaded conveyor rollers travel over the metal strip because the upper chain flights travel at two different levels. The following rollers arrive thus at a higher level than that at which the rollers are traveling which are withdrawn from below the sheet metal strip.

The prior known stacking arrangement has a number of disadvantages which are to be eliminated with the arrangement of the present invention. First, the piror art arrangement requires an additional chain Wheel pair in order to force the upper flight of the chain in the direction of movement from a higher level to a lower level. The spacing between the conveyor rollers, which are rigidly secured to the chains, cannot be made selectively small because within a roller interval, a sheet metal strip edge must be placed between the last carrying roller and the first roller which follows it at the higher level. Furthermore, it must be regarded as unfavorable for the purpose of obtaining a scratch-free stacking of the sheet metal strips, that the strips travel during the depositing thereof on the stack between two rollers which are moved at the same level, of which the front roller still supports the sheet metal strip while the subsequent roller presses the sheet metal strip down from above. The thicker the sheet metal strips are, the more properly is the depositing of the strips accomplished, but even in that case scratches sometimes are made in the surface of the sheet metal strips.

On the basis of a stacking arrangement of the above described type in which the sheet metal supports, for example, rollers arranged between support chains are withdrawn from below the sheet metal strip, after a strip has abutted against a front stop While the subsequent rollers travel one after the other through an adjusted level position above the metal strip, it is an object of the invention to avoid any pressure of the rollers on the sheet metal strip that would go beyond a contact pressure based on the weight of the sheet metal strip. However, a simple endless conveyor arrangement for continuous operation is to be retained in view of the output capacity of the stacking arrangement.

According to the invention, the above described stacking arrangement is improved in that the rollers of the conveyor arrangement are not mounted rigidly to their support chains but are connected so as to be freely movable vertically and that the upper flights of the chains are moved horizontally throughout.

The advantage of the invention results in the fact that the difference in level of the rollers in their travel with the upper flight of the chain is not produced by a forcible downward guiding of the chains themselves but in that the conveyor rollers are movable vertically relative to their chains and that such construction may be obtained in different Ways. According to the invention it is preferable to provide mobility of the conveyor rollers by means of an oscillating connection to the support chains, wherein the rollers are movable during their travel with the upper flight by means of an oscillating deflection of oscillating arms between two vertical positions. A particularly pre ferred arrangement for changing the vertical position of the conveyor rollers by a deflection of the oscillating arms from the suspended position consists in that the oscillating arms carry loose support rollers spaced from their pivoting axis, which support rollers travel on rails of different vertical levels.

Two embodiments of a stacking arrangement for surface sensitive strips are illustrated diagrammatically in the drawing, in which:

FIG. 1 is a side view,

FIGS. 2 through 6 show various stages in the operation of the arrangement,

FIG. 7 shows a cross-section alone line VII-VII in FIG. 1,

FIGS. 8 and 10 show two embodiments of support shafts with conveyor rollers,

FIGS. 9 and 11 show cross-sections along lines 11-11 and IV-IV in FIG. 8 or 10, and

FIG. 12 shows a portion of the conveyor arrangement with support shafts according to FIGS. 8 and 9.

From FIG. 1 may be seen that around a stacking table 1 an endless conveyor is arranged which has an upper flight 2, a lower fllight 3 and vertical flights 4 and 5. The stacking table 1 rests on wheel pairs 6 located on rails 7, which in turn are supported by the underframe 8. Hydraulic or pneumatic lifting blocks 9 and 10 serve to lower and lift the stacking table which may be moved out over connecting rails, not shown, when it is in its lowest position. To the actual so-called stacking box there are further provided side walls 11 and 12 which may be adjustable to various lengths of sheet metal strips.

The special features of the roller conveyor may be seen from the cross-section according to FIG. 7. For a straight guiding of the upper flight 2 there are employed first two pairs of U-shaped metal members 13 and 14, on the upper legs of which roller pairs 15 and 16 are guided and which are positioned in pairs on shafts 17 and 18, respectively. These shafts carry between the rollers, link members 19 and 20 to which the roller chains 21 and 22 of the endless conveyor are connected.

At the inwardly facing ends of the shaft 17 and 18 roller shafts 23 having disc-shaped rollers 24 are oscillatably mounted by means of arms 25 and 26. In this manner the conveyor rollers 23, 24 are connected in a vertically adjustable manner relative to the chains 21 and 22 because the oscillating arms 25 and 26 may pivot out of the vertically hanging stable position determined by the weight of the rollers and in this manner the conveyor rollers may be brought to a different level.

In this arrangement theroller shafts 23 are hollow and are pushed over support shafts 23a on which they are mounted rotatably. The support shafts 23a are provided support rollers 38 and 39 and by rails 44 and 41 associated therewith, depending on the course of theserails;

As may be seen from FIGS. 1 through 6, the rails 4t r up theweight of the sheet metal they must be made strong. With this, the outerdiameter of the conveyor and 41 lie in a path in front of thestacking table and at such a small distance from the upper flight 2 of the chains that the oscillating arms 25,;26 may be rocked outwardly so as to provide a higher support position of the conveyor rollers 24. The oscillating arms may be deflected up to the horizontal level. In this higher support position the rollers 24 take up the sheet metal strips34 from the conveyorbelt35. While the. support rollers 38 and; 39 are traveling on their rails.40 and 41 the conveyorrollers 24 support the sheet metal strip. in the plane thereof.

The arrangement is "such that the large deflection of the rollers, upon their entering into the vicinity of the stacking.table,.is notentirelydone away withby eliminating the rails for the supportrollers 38 and 39 but by con side 2 ofthe moving track corresponds tothe level of the traveling roller shafts 17 and 18. For reasons of simplicity the. chain wheels 27 are illustrated with reference to the moving track ofrthese shafts, although itis obvious that they cooperate with the chain trains21 and 22 After a sheet metal strip has been deposited on the sheet metal strip stack theqstackingtableul is moved downwardly by. one sheet'metal ,strip thickness as is indicated in FIG. 6 by meansof arrow A. p

In the embodiment of the invention described so far, the conveyor rollers were arranged concentrically of their supporting shafts." Since the supporting shafts must take rollers also increases." But the level difference between the rollers which are deflected into a higher supporting position and the rollers located at the vertically oralmost' vertically hanging oscillating arms depends onthe roller diameten 1 r It has been recognized that the", enforced large level difference in the concentric conveyor rollers may adversely influence the operating safety'of the stacking arrangement 7 because the sheet metal strips, 'Wllll their free front edge which is lowerinrthe area of the downwardly movable rollers may, due to theirben ding or especiallyin the case tinuing them above the stacking .table at. alowerlevel than beforeto .still deflect the oscillating arms somewhat from the. freely hanging position. The-rails in the area of the stacking arrangement. according clination,"travel under the front stop between two rollers.

Furthermore, because of the concentric arrangement of the conveyo'rrollers relative to the supporting shaft, the

come from the conveyor belt'35. onto theconveyor rollers 24 whichare constrained, in the vicinity of rails '40 'and 41,to a higher. supportinglevel at which the oscillating arms 25 and 26 are pivoted far rearwardly relative to the If in front of a sheet metal .strip. 34 no other 'sheet metal strip is located, the

direction of travel of the chains.

conveyor rollers are lowered in the area above the stack- 21' and 22 and by their own weight, due to the difference in levelof the rails 4ilaand 41a, to such'adegree that the oscillating arms are still moved to a somewhat de-;.

flected position and free ofoscillatory movement. The

sheetmetal strip 34 will bend at its forward portion-deg tion on the stacking-table. This process is illustrated in FIGS.. Zthrough 6. In this-'arrangement the conveyor rollers must be rotatable independently of the support" rollers 38 and. 39 because the latter have a different rota-.

tion during their simultaneous travel on "therails 40a and41a.--'.

When the conveyor rollers have traveled further rela tive to the position in FIG, 1 by one roller interval'(FIG.'

2) the first COHVBYOT'I'OHGI"24bWhlGl1 was still left in the higher supporting position travelsautomatically overthe sheet metal strip 32 forwardly thereof and in a similar way the subsequent rollers follow as shown in FIGS. 3 I

through 6. 1 In this instance a special control is not neces-i sary because each of. the sheet metal-strips located at the front stop directs the subsequent rollers automatically over itself. a

. For abetter understanding of the schematic illustra-' tion of the conveyor arrangement in FIGS. 1" through 6 it should be mentioned that thefline depicting the upper j in FIGS. ,8 through 12.

consequence may be that the direction of rotationof the rollers'which travel over a stationary sheet metal strip have imparted'to a sheet'metal .strip which is supported.

which is conveyor rollers are arranged on support shafts eccen-' trically of and onv both sidesxof the center axis of the support shafts approximately .ina plane containingthe oscillatingarms and .on special roller shafts which are connected to the support shafts as illustrated more clearly Oscillating arms 25 and 26 are connected to the shafts 17 and lsjwhich. are carried by the rotating conveyor chains. To these arms strong support shafts 23b (FIGS.

8 and 9) or;-23c .(FIGS, 10 and 11), preferably rectangular in cross-section,--are connected non-rotatably. On the extension-of the support shafts loose support rollers 38 and 39 are mounted which travel over rails 40'a'nd 41 whichdetermine the vertical position of the support shafts by deflectionof the oscillating arms 25, 26.

46which travelin bearing As may be seen from FIGS. 8'through 11, the preferably roller-shaped conveyor rollers M nd 45 are arranged eccentri'cally. withrespect to the. support sh'aft with theihaxes. in a plane containing the oscillating'arms 25, 26. .The rollers are mounted on special roller shafts blocks 47 "on the support shafts. 1 V j In the embodiment accordingon FIGS.'1O and 11 the support shafts 230 are bent downwardly in the center along the Widthof the front stop 33. The rollers in this 1 instanceliein pairs.- diametrically of the axes of the nonbent'ends'of the support shafts;v The'bending makes it is'obviated. FIGURE 12 illustrates the'desired improvement of the possible'j to adjust the, front .stop substantially lower than the support plane'of the upper supporting rollers 44 whereby the danger of metal strips travelling thereunder stacking'arrangernent withrespect to .thelevel difference of'the supporting rollers 44; Before the rails 40, 41 are deflected downwardly to 'becomethe lower course rails 40a, 41a, the oscillatingarm s 25,126 are deflected almost. 'to the horizontal position,the rollers 44 carrying a strip 32. From this'itin ay befseen, first,that the support rollers 44 which lie closest to the pivot points 48 of the oscillating arms now lead the support shafts. They thus support the sheet metal front edges for a longer time than in the case of a concentric arrangement of the rollers on the support shafts so that the sheet metal strips are prevented for a longer time from tilting downwardly.

When the oscillating members begin to deflect until the rollers 45 are positioned against the strip 32 lying against the front stop in a lower position, the distance between the lower rollers 4-5 which exceeds the length of the oscillating members has a favorable effect in that the angle of movement of the oscillating arms becomes smaller than that which occur with a concentric roller arrangement. This means that the supporting rollers 44 undergo a smaller lowering action. Short strips which might tilt downwardly at their forward portions immediately receive in that case a support again at their rearward position so that they cannot undergo such an inclination as could cause a forward movement beneath the stop. The reduced level difference is illustrated in FIG.

12 with a small a.

What is claimed is:

I. In a stacking arrangement for sheet metal strips, a horizontal table upon which the sheets are stacked, a conveyor for feeding the sheets to the table comprising endless flexible means movable in a horizontal plane along the table, a plurality of spaced roller devices, means suspendiing the roller devices from the flexible means for pivotal movement relative thereto and for translation thereby toward the table, means cooperating with the roller devices during their approach to the table for maintaining them at an upper predetermined level above the plane of the table at which at least a pair of rollers devices supports a sheet for conveyance toward the table, second means cooperating with the roller devices for guiding and maintaining them at a level lower than the predetermined level and above the table as they reach the table, and abutment means engageable with the forward edge of the sheet while supported on the roller devices when entirely positioned over the table to permit sequential withdrawal of the roller devices from beneath the sheet and sequential travel of the following roller devices over the sheet from which the preceding roller devices are being withdrawn.

2. In a stacking arrangement for sheet metal strips, a horizontal table upon which the sheets are to be stacked, a conveyor for feeding the sheets to the table comprising, endless flexible means movable in a horizontal plane above the table, a plurality of roller devices, means suspending the roller devices pivotally from said flexible means in spaced relation to each other for translation thereby toward the table, means for deflecting the roller devices during their approach to the table to position them at an upper predetermined level above the plane of the table at which at least a pair of roller devices supports a sheet for conveyance toward the table, second deflecting means cooperating with the roller devices for guiding them to a lower level above the table as they reach the table, and abutment means engageable with the forward edge of the sheet while supported by the roller devices when entirely positioned over the table to permit sequential withdrawal of the roller devices from beneath the sheet and sequential travel of the following roller devices over the sheet from beneath which the preceding roller devices are being withdrawn.

3. In a stacking arrangement as defined by claim 2, in which the flexible means comprises a pair of spaced parallel chains, said roller devices lying transversely of the chains and oscillatably suspended by a pair of arms connected to the respective chains.

4. In a stacking arrangement as defined by claim 2, in which the flexible means comprises a pair of spaced parallel chains, said roller devices lying transversely of the chains, a pair of spaced arms oscillatably suspending each of the roller devices from the chains, said first and second means for deflecting the roller devices including a rail below and parallel to each of the chains, and means supported by the arms in contact with the rails.

5. In a stacking arrangement as defined by claim 4, in which the roller devices comprise a supporting shaft oscillatably suspended from the arms, and rollers rotatably mounted on the shaft on diametrically opposite sides of the axis thereof with the axes of the rollers in a plane containing the arms.

6. In a stacking arrangement as defined by claim 4, wherein the roller devices comprise a supporting shaft rotatably connected to said oscillatable arms, and rollers rotatably mounted on said supporting shaft in spaced axial relationship and coaxially with said shaft.

'7. In a stacking arrangement as defined in claim 5 wherein said supporting shaft is non-rotatably connected to said arms.

3. In a stacking arrangement as defined in claim 7 wherein individual rollers are mounted rotatably on the top and bottom sides of said non-rotatable supporting shaft at relatively displaced axial positions.

9. In a stacking arrangement as defined in claim 7, wherein a plurality of rollers are mounted in pairs at diametrically opposite sides of said supporting shafts.

it). In a stacking arrangement as defined in claim 9, wherein abutment means are disposed at a lower level than the level of said supporting shaft, said supporting shaft having a downwardly curved central portion adapted to' pass under said abutment means, said roller pairs being disposed on each side of said central curved portion.

References Qited by the Examiner UNITED STATES PATENTS 5/35 Conldin 271-86 10/40 Schaefer 198l83 

1. IN A STACKING ARRANGMENT FOR SHEET METAL STRIPS, A HORIZONTAL TABLE UPON WHICH THE SHEETS ARE STACKED, A CONVEYOR FOR FEEDING THE SHEETS TO THE TABLE COMPRISING ENDLESS FLEXIBLE MEANS MOVABLE IN A HORIZONTAL PLANE ALONG THE TABLE, A PLURALITY OF SPACED ROLLER DEVICES, MEANS SUSPENDING THE ROLLER DEVICES FROM THE FLEXIBLE MEANS FOR PIVOTAL MOVEMENT RELATIVE THERETO AND FOR TRANSLATION THEREBY TOWARD THE TABLE, MEANS COOPERATING WITH THE ROLLER DEVICES DURING THEIR APPROACH TO THE TABLE FOR MAINTAINING THEM AT AN UPPER PREDETERMINED LEVEL ABOVE THE PLANE OF THE TABLE AT WHICH AT LEAST A PAIR OF ROLLERS DEVICES SUPPORTS A SHEET FOR CONVEYANCE TOWARD THE TABLE, SECOND MEANS COOPERATING WITH THE ROLLER DEVICES FOR GUIDING AND MAINTAINING THEM AT A LEVEL LOWER THAN THE PREDETERMINED LEVEL AND ABOVE THE TABLE AS THEY REACH THE TABLE, AND ABUTMENT MEANS ENGAGEABLE WITH THE FORWARD EDGE OF THE SHEET WHILE SUPORTED ON THE ROLLER DEVICES WHEN ENTIRELY POSITIONED OVER THE TABLE TO PERMIT SEQUENTIAL WITHDRAWL OF THE ROLLER DEVICES FROM BENEATH THE SHEET AND SEQUENTIAL TRAVEL OF THE FOLLOWING ROLLER DEVICES OVER THE SHEET FROM WHICH THE PRECEDING ROLLER DEVICES ARE BEING WITHDRAWN. 